package com.hmdp.service.impl;

import cn.hutool.core.bean.BeanUtil;
import com.hmdp.dto.Result;
import com.hmdp.entity.SeckillVoucher;
import com.hmdp.entity.VoucherOrder;
import com.hmdp.mapper.VoucherOrderMapper;
import com.hmdp.service.ISeckillVoucherService;
import com.hmdp.service.IVoucherOrderService;
import com.baomidou.mybatisplus.extension.service.impl.ServiceImpl;
import com.hmdp.utils.RedisIdWorker;
import com.hmdp.utils.SimpleRedisLock;
import com.hmdp.utils.UserHolder;
import lombok.extern.slf4j.Slf4j;
import org.redisson.api.RLock;
import org.redisson.api.RedissonClient;
import org.springframework.aop.framework.AopContext;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.core.io.ClassPathResource;
import org.springframework.data.redis.connection.stream.*;
import org.springframework.data.redis.core.StringRedisTemplate;
import org.springframework.data.redis.core.script.DefaultRedisScript;
import org.springframework.stereotype.Service;
import org.springframework.transaction.annotation.Transactional;

import javax.annotation.PostConstruct;
import java.time.Duration;
import java.time.LocalDateTime;
import java.util.Collections;
import java.util.List;
import java.util.Map;
import java.util.concurrent.ArrayBlockingQueue;
import java.util.concurrent.BlockingQueue;
import java.util.concurrent.ExecutorService;
import java.util.concurrent.Executors;

/**
 * <p>
 *  服务实现类
 * </p>
 *
 * @author 虎哥
 * @since 2021-12-22
 */
@Service
@Slf4j
public class VoucherOrderServiceImpl extends ServiceImpl<VoucherOrderMapper, VoucherOrder> implements IVoucherOrderService {


    @Autowired
    private ISeckillVoucherService seckillVoucherService;

    @Autowired
    private RedisIdWorker redisIdWorker;

    @Autowired
    private StringRedisTemplate stringRedisTemplate;

    @Autowired
    private RedissonClient redissonClient;
    private static final DefaultRedisScript<Long> SECKILL_SCRIPT;
    static {
        SECKILL_SCRIPT=new DefaultRedisScript<>();
        SECKILL_SCRIPT.setLocation(new ClassPathResource("seckill.lua"));
        SECKILL_SCRIPT.setResultType(Long.class);
    }



    private static final ExecutorService SECKILL_ORDER_EXECUTOR= Executors.newSingleThreadExecutor();

    @PostConstruct
    private void init(){
        SECKILL_ORDER_EXECUTOR.submit(new VoucherOrderHandler());
    }

    private class VoucherOrderHandler implements Runnable{

        String queueName="stream.orders";

        @Override
        public void run() {
            while (true){

                try {
                    //1.获取消息队列中的订单信息
                    List<MapRecord<String, Object, Object>> list = stringRedisTemplate.opsForStream().read(
                            Consumer.from("g1", "c1"),
                            StreamReadOptions.empty().count(1).block(Duration.ofSeconds(2)),
                            StreamOffset.create(queueName, ReadOffset.lastConsumed())
                    );
                    //2.判断消息获取是否成功
                    if (list==null||list.isEmpty()){
                        //2.1.如果获取失败，没有消息，继续下一次循环
                        continue;
                    }
                    //解析消息中的订单信息
                    MapRecord<String, Object, Object> record = list.get(0);
                    Map<Object, Object> values = record.getValue();
                    VoucherOrder voucherOrder = BeanUtil.fillBeanWithMap(values, new VoucherOrder(), true);
                    //3.如果获取成功，可以下单
                    handleVoucherOrder(voucherOrder);
                    //4.ACK确认
                    stringRedisTemplate.opsForStream().acknowledge(queueName,"g1",record.getId());
                } catch (Exception e) {
                    log.error("处理订单异常",e);
                    handlePendingList();
                }
            }
        }

        private void handlePendingList() {
            while (true){

                try {
                    //1.获取PendingList中的订单信息
                    List<MapRecord<String, Object, Object>> list = stringRedisTemplate.opsForStream().read(
                            Consumer.from("g1", "c1"),
                            StreamReadOptions.empty().count(1),
                            StreamOffset.create(queueName, ReadOffset.from("0"))
                    );
                    //2.判断消息获取是否成功
                    if (list==null||list.isEmpty()){
                        //2.1.如果获取失败，说明pending-lis没有消息，继续下一次循环
                        break;
                    }
                    //解析消息中的订单信息
                    MapRecord<String, Object, Object> record = list.get(0);
                    Map<Object, Object> values = record.getValue();
                    VoucherOrder voucherOrder = BeanUtil.fillBeanWithMap(values, new VoucherOrder(), true);
                    //3.如果获取成功，可以下单
                    handleVoucherOrder(voucherOrder);
                    //4.ACK确认
                    stringRedisTemplate.opsForStream().acknowledge(queueName,"g1",record.getId());
                } catch (Exception e) {
                    log.error("处理pending-list订单异常",e);
                    try {
                        Thread.sleep(20);
                    } catch (InterruptedException ex) {
                        throw new RuntimeException(ex);
                    }
                }
            }

        }
    }


/*    private BlockingQueue<VoucherOrder>orderTasks =new ArrayBlockingQueue<>(1024*1024);
    private class VoucherOrderHandler implements Runnable{

        @Override
        public void run() {
            while (true){

                try {
                    //1.获取队列中的订单信息
                    VoucherOrder voucherOrder = orderTasks.take();
                    //2.创建订单
                    handleVoucherOrder(voucherOrder);

                } catch (Exception e) {
                    log.error("处理订单异常",e);
                }
            }
        }
    }*/

    private void handleVoucherOrder(VoucherOrder voucherOrder) {
        //1.获取用户
        Long userId = voucherOrder.getUserId();
        //2.创建锁对象
      //*  SimpleRedisLock lock = new SimpleRedisLock("order:" + id, stringRedisTemplate);*//*
        RLock lock = redissonClient.getLock("order:" + userId);
        //3.获取锁
        boolean isLock = lock.tryLock();
        //4.判断获取锁是否成功
        if (!isLock){
            //获取锁失败
            log.error("不运行重复下单");
            return ;
        }

        try {
             proxy.createVoucherOrder(voucherOrder);
        } finally {
            //释放锁
            lock.unlock();
        }
    }
    
    private IVoucherOrderService proxy;
    @Override

    public Result seckillVoucher(Long voucherId) {
        //获取用户id
        Long userId = UserHolder.getUser().getId();
        //获取订单id
        long orderId = redisIdWorker.nextId("order");
        //1.执行lua脚本
        Long result = stringRedisTemplate.execute(
                SECKILL_SCRIPT,
                Collections.emptyList(),
                voucherId.toString(), userId.toString(), String.valueOf(orderId)
        );
        //3.获取代理对象
        proxy = (IVoucherOrderService) AopContext.currentProxy();
        //4.返回订单id
        return Result.ok(orderId);
    }

/*    @Override

    public Result seckillVoucher(Long voucherId) {
        //获取用户id
        Long userId = UserHolder.getUser().getId();
        //1.执行lua脚本
        Long result = stringRedisTemplate.execute(
                SECKILL_SCRIPT,
                Collections.emptyList(),
                voucherId.toString(), userId.toString()
        );
        //2.判断结果是否为0
        int r = result.intValue();
        if (r!=0){
            //2.1.不为0，代表没有购买资格
            return Result.fail(r==1?"库存不足":"不能重复下单");
        }
        //2.2.为0，有购买资格，把下单信息保存到阻塞队列
        VoucherOrder voucherOrder = new VoucherOrder();
        //2.3.创建订单id
        long orderId = redisIdWorker.nextId("order");
        voucherOrder.setId(orderId);
        //2.4.用户id
        voucherOrder.setUserId(userId);
        //2.5.代金卷id
        voucherOrder.setVoucherId(voucherId);
        //2.6.放入阻塞队列
        orderTasks.add(voucherOrder);
        //3.获取代理对象
        proxy = (IVoucherOrderService) AopContext.currentProxy();
        //4.返回订单id
        return Result.ok(orderId);
    }*/
/*    @Override

    public Result seckillVoucher(Long voucherId) {
        //1.查询优惠卷
        SeckillVoucher voucher = seckillVoucherService.getById(voucherId);
        //2.判断秒杀是否开始
        if (voucher.getBeginTime().isAfter(LocalDateTime.now())) {
            //尚未开始
            return Result.fail("秒杀尚未开始!");
        }
        //3.判断秒杀是否结束
        if (voucher.getEndTime().isBefore(LocalDateTime.now())) {
            //已经结束
            return Result.fail("秒杀已经结束!");
        }
        //4.判断库存是否充足
        if (voucher.getStock() < 1) {
            //库存不足
            return Result.fail("库存不足!");
        }

        Long id = UserHolder.getUser().getId();

        //创建锁对象
      *//*  SimpleRedisLock lock = new SimpleRedisLock("order:" + id, stringRedisTemplate);*//*
        RLock lock = redissonClient.getLock("order:" + id);
        //获取锁
        boolean isLock = lock.tryLock();
        //判断获取锁是否成功
        if (!isLock){
            //获取锁失败
            return Result.fail("不允许重复下单");
        }

        try {
            //获取代理对象
            IVoucherOrderService proxy = (IVoucherOrderService) AopContext.currentProxy();
            return proxy.createVoucherOrder(voucherId);
        } finally {
            //释放锁
            lock.unlock();
        }
    }*/



    @Transactional
    public   void createVoucherOrder(VoucherOrder voucherOrder) {
        //5.一人一单
        Long id = voucherOrder.getUserId();
            //5.1.查询订单
            int count = query().eq("user_id", id).eq("voucher_id", voucherOrder.getVoucherId()).count();
            //5.2.判断是否存在
            if (count > 0) {
                //用户已经购买过
                log.error("用户已经购买过");
                return ;
            }

            //6.扣减库存
            boolean success = seckillVoucherService.update()
                    .setSql("stock=stock-1") //set stock=stock-1
                    .eq("voucher_id", voucherOrder.getVoucherId()).gt("stock", 0) //where id=?and stock=?
                    .update();
            if (!success) {
                log.error("库存不足!");
                return ;
            }
            //7.创建订单
            save(voucherOrder);
    }
}

